It's a simple app to use. The child simply puts the pictures in the correct order and is rewarded by a simple video. You can read a review of the app here. I felt the $2.99 price was reasonable.

The app itself is simple, and does not collect data. You need to control the quick little fingers on the ipad a bit to minimize random guessing.

In other words, you just can't turn a kid loose on it without control.

What I really like about it is the extension activities for writing that I've come up with.

I let the kids use this app a bit, having them verbalize sentences to go with the pictures, and answer my questions.

Then I take away the ipad, and provide them screenshot print outs of a selected set of pictures. The task is to write out the sequence using complete sentences and transition words. For whatever reason, my students have been very motivated to do this, and I've been amazed by some significantly handicapped children's abilities here.

The kids are not writing "War and Peace", but they are providing me with little written stories to go with the pictures. I can then expand on the sentences with them, and model appropriate syntax and vocabulary. The reward for their efforts is more Milo Sequencing! The students' teacher loves this too, and is eager to use the screenshot printouts during her writing activities.

Screenshot printout, with my student's writing

If you need to know how to take a screenshot with your iPad, go here for a tutorial.
You can then find the photo in your gallery, and just email it to yourself to print from a computer.

As a disclaimer, I found this app and paid for it myself. No one asked me to write about it, but a few of my students with autism especially love it, so I use it.